Manitowoc Ice S1800 Analyzing Discharge Pressure During Freeze or Harvest Cycle, Procedure

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Refrigeration System	Section 7

ANALYZING DISCHARGE PRESSURE DURING FREEZE OR HARVEST CYCLE

Procedure

1. Determine the ice machine operating conditions:

Air temp. entering condenser	______
Air temp. around ice machine	______
Water temp. entering sump trough	______

2.Refer to Operating Pressure Chart for ice machine being checked.

Use the operating conditions determined in step 1 to find the published normal discharge pressures.

Freeze Cycle _______

Harvest Cycle _______

Freeze Cycle Discharge Pressure High Checklist

3. Perform an actual discharge pressure check.

	Freeze Cycle	Harvest Cycle
	PSIG (kPa)	PSIG (kPa)
Beginning of Cycle	__________	__________
Middle of Cycle	__________	__________
End of Cycle	__________	__________

4.Compare the actual discharge pressure (step 3) with the published discharge pressure (step 2).

The discharge pressure is normal when the actual pressure falls within the published pressure range for the ice machine’s operating conditions.

Possible Cause		Check/Correct
Improper installation		See “Installation/Visual Inspection Checklist”
Restricted condenser water flow		Low water pressure [20 psi (138 kPa) min.]
		High inlet water temperature (90°F/32.2°C max.)
		Dirty condenser
		Dirty/defective water regulating valve
		Water regulating valve out of adjustment
Improper refrigerant charge		Overcharged
		Non-condensables in system
		Wrong type of refrigerant
Other		Non-Manitowoc components in system
		High side refrigerant lines/component restricted (before mid-condenser)
Freeze Cycle Discharge Pressure Low Checklist

Possible Cause	Check/Correct
Improper installation	See “Installation/Visual Inspection Checklist”
Improper refrigerant charge	Undercharged
	Wrong type of refrigerant
Water regulating valve	Out of adjustment
	Defective
Other	Non-Manitowoc components in system

NOTE: Do not limit your diagnosis to only the items listed in the checklists.

7-12	Part Number 80-1634-3

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Contents Service Manual Read These Before Proceeding Personal Injury PotentialTable of Contents Table of Contents Section Ice Machine Operation Section MaintenanceSection Before Calling For Service Table of Contents Section Electrical System Section Refrigeration SystemTable of Contents Ice Cube Sizes How to Read a Model NumberModel Numbers Self-Contained Water-CooledGeneral Information Section Accessories Section General Information Model/Serial Number Location Model/Serial Number LocationWarranty Coverage Electrical and AuCS Dimensions Ice Machine DimensionsWidth, Depth, and Height Dimensions GeneralS1800M Water-Cooled Installation Instructions Section Location of Ice MachineIce Machine Heat of Rejection Series Heat of Rejection Ice Machine Air ConditioningMinimum Circuit Ampacity Section Installation Instructions Electrical ServiceVoltage Electrical RequirementsSelf Contained ICE Machine 208-230/3/60 For United Kingdom OnlySelf Contained ICE Machine 115/1/60 or 208-230/1/60 Self Contained ICE Machine 230/1/50Water Inlet Lines Cooling Tower ApplicationsWater Supply Drain ConnectionsWater Supply and Drain Line SIZING/CONNECTIONS Installation Instructions SectionTypical Water Supply Drain Installation CondenserSection Installation Instructions Installation Check List AuCS Automatic Cleaning System Potential Personal Injury SituationSection Ice Machine Operation Component IdentificationIce Machine Operation Section Sequence Of Operation Initial START-UP or START-UP After Automatic SHUT-OFFHarvest Safety TimersHarvest Sequence 5. Water Purge Automatic SHUT-OFF 7. Automatic Shut-OffICE Thickness Check Ice Machine Operation Section Operational ChecksWater Level Ice Thickness CheckWater Purge Adjustment Harvest Sequence Water PurgeIce Machine Operation Section This page Intentionally Left BlankWater-Cooled Condenser Water Regulating Valve Exterior CleaningIce Machine Inspection AlphaSan→Sachet Replacement Frequency Maintenance Section GuardianInstallation Sachet Replacement ProcedureModel Amount of Cleaner Section Maintenance Interior Cleaning and SanitizingCleaning Procedure StepMaintenance Section Sanitizing ProcedureSolution Type Water Mixed With Sanitizer Removal of Parts for CLEANING/SANITIZING Solution Type Water Mixed WithWater Curtain Water Curtain Removal Ice Thickness ProbeIce Thickness Probe Removal Water Distribution Tube Water TroughWater Distribution Tube Removal Water Level Probe Water PumpWater Pump Removal Dump Valve Disassembly Water Dump ValveEvaporator Tray Removal Drain Line Check ValveWater Inlet Valve Maintenance Section Removal from Service/Winterization Pry Open the Water Regulating Valve AUCS→ AccessorySELF-CONTAINED WATER-COOLED ICE Machines Checklist Problem Possible Cause To CorrectBefore Calling For Service Section Safety Limit FeatureEnergized Parts Charts Section Electrical SystemSELF-CONTAINED WATER-COOLED Models Water Purge SELF-CONTAINED ModelsInitial Start-Up or Start-Up After Automatic Shut-Off Self-Contained Water PurgeRefrigeration System Start Up 5 Seconds Toggle Switch Refrigeration System START-UPSelf-Contained Refrigeration System Start-Up PRE-CHILL Electrical System SectionFreeze Sequence Self-Contained Pre-Chill Self-Contained ModelsToggle Switch Bin Switch Control Board Relays FreezeSelf-Contained Freeze Self-Contained Models Harvest Sequence Harvest Automatic Shut-Off Automatic SHUT-OFFSelf-Contained Automatic Shut-Off Section Electrical System Wiring Diagrams Wiring Diagram LegendS1800 SELF-CONTAINED 1 Phase Control BoardS1800 SELF-CONTAINED 3 Phase BIN Switch SpecificationsCheck Procedure Main FuseContinuity Test SymptomsDiagnostic Aids Water Curtain Removal NotesCheck Motor Windings to Ground Compressor Electrical DiagnosticsCheck Resistance Ohm Values Determine if the Compressor is SeizedPtcr Diagnostics What is a PTCR?Compressor Start Sequence Model Automatic Shut-Off and Restart Troubleshooting PTCR’sWHY a Good Ptcr MAY Fail To Start the Compressor During Start-Up First .25 1.0 SecondsModel Manitowoc Cera-Mite Room Checking the PtcrManitowoc Ptcr Part NumberRelay Diagnosing Start ComponentsCapacitor Relay Operation CheckICE/OFF/CLEAN Toggle Switch Switch Setting Terminals Ohm ReadingElectronic Control Board Control BoardSafety Limits InputsHOW the Probe Works Freeze Time LOCK-IN FeatureIce Thickness Probe Cleaning Harvest LightDiagnosing ICE Thickness Control Circuitry Monitoring of Harvest Light CorrectionWater Level Probe Light Water Inlet Valve Safety SHUT-OFFElectrical System Section Water Level Control Circuitry Freeze Cycle CircuitryProblem Water Trough Overfilling During Freeze Cycle Diagnosing Water Level Control CircuitryWait until the freeze cycle starts On or OFF Step Check Self Contained 1 Phase with Terminal Board SELF-CONTAINED Water -COOLED Models Freeze Cycle Refrigeration SequenceRefrigeration System Section S1800 SELF-CONTAINED Tubing Schematic General ICE Production Check Before Beginning ServiceWeights are in pounds Times are in minutesINSTALLATION/VISUAL Inspection Checklist Water System ChecklistPossible Problem Corrective Action ICE Formation Pattern Extremely Thin at Evaporator OutletNormal Ice Formation Extremely Thin at Evaporator Inlet No Ice FormationSafety Limits Safety Limit IndicationAnalyzing Why Safety Limits May Stop the Ice Machine Safety Limit Notes Possible Cause Check/CorrectSection Refrigeration System Freeze Cycle Discharge Pressure Low Checklist ProcedureFreeze Cycle Discharge Pressure High Checklist Analyzing Discharge Pressure During Freeze or Harvest CycleStep Example Using SY1004A Model Ice Machine Analyzing Suction Pressure During Freeze CycleFreeze Cycle Suction Pressure High Checklist Freeze Cycle Suction Pressure Low ChecklistHarvest Valve Temperature Check General Harvest Valve AnalysisFindings Comments Discharge Line Temperature Analysis General Column 2 LOW CHARGE/TXV Starving Final AnalysisColumn 1 Harvest Valve Leaking Column 3 TXV FloodingRefrigeration System Operational Analysis Tables Models Dual Expansion Valve Ice Machine Model NumberHigh Pressure CUT-OUT Hpco Control Hour Ice Production S1800 SeriesSelf-Contained Water-Cooled Cycle Times Operating PressuresSELF-CONTAINED RECOVERY/EVACUATION ConnectionsSelf-Contained Charging Procedures Charging ConnectionsSystem Contamination CLEAN-UP Determining Severity Of ContaminationMild System Contamination Cleanup Procedure Severe System Contamination Cleanup ProcedureSection Refrigeration System 10. Using Pinch-Off Tool FILTER-DRIERS Drier End Part Model Connection Size NumberTotal System Refrigerant Charges Series Version Charge S1800M48 oz Refrigerant Definitions RecoverNew Product Specifications RecycleNew Refrigerant Recovered or Recycled RefrigerantRefrigerant RE-USE Policy Reclaimed RefrigerantHFC Refrigerant Questions and Answers This page Intentionally Left Blank Page Attend a Manitowoc Factory Service School